1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor device having a semiconductor element over a substrate with an insulating film therebetween.
2. Description of the Related Art
As a conventional method for manufacturing a polycrystalline semiconductor used for a thin film device such as an insulated-gate field-effect transistor, there is a method which employs a laser annealing method (for example, see Patent Document 1: Japanese Published patent application No. H 5-182923). Specifically, a silicon oxide film which is a base protective film is formed over a glass substrate, and an amorphous silicon film is formed over the silicon oxide film. Subsequently, heat annealing is performed to reduce the concentration of hydrogen contained in the amorphous silicon film, and a KrF excimer laser beam is irradiated onto the amorphous silicon film to crystallize the amorphous silicon film, thereby forming a polycrystalline silicon film.